In Workspace you can add in some free text as a visualization or panel type. Which can help explain what's going on. Same with Dashboards. Regular reports do have a note section at the bottom. I believe you need to be an admin to add notes though to regular reports.
The calendar entries you make will automatically show in trended / over time reports. Assuming you have access to the tool, I recommend exploring a few events and then looking at the reports to see how it behaves.
You can also control who can see them by sharing with other users too